yeah they do have dog tags.
I have a blood clotting disorder, so while I have one I only wear it if I'm in a place where I can get cut up. So skiing, I've had a full leg laceration before, that was cute... Also when I'm scuba diving. Usually with buddies that may or may not remember about it and since I'm wet I won't have my wallet on me.
http://www.americanmedical-id.com/marketplace/category.php?sel_pullid=9
That's basically the one I have, can't remember who it's from though.
So mine is basic, stainless steel. I dive a lot so didn't want silver due to tarnish, and since I don't wear it all the time I couldn't see spending a boatload for some other wacky metal. Stainless goes just fine with my watch :-D not so much with the wedding ring, but that doesn't do me any good if I bleed out anyway. Left hand gets so busy...
Not sure of any service per se associated with it, but no I have not had to have an EMT flip it over as I've been conscious each time I've been carried off *been too many times... They do however always ask about it when they've seen it, and then will usually double check just to make sure I didn't omit anything.
If you're planning on wearing it every day, I would treat it just like you would the purchase of a watch. Not sure what your day job is, but if you have a gold watch, you don't want a silver band and vice versa. Sorry to hear that you need to wear one, but best of luck
